Cytochrome dehydrogenase

The results on Table 2 shows a Methylene Bisthiocyanate based biocide. The mechanism of action of this biocide is to block the transfer of electrons from primary cytochrome dehydrogenase, and thereby cause an uncoupling of oxidative phosphorylation . Here the Total ATP results initially increase on treatment with the biocide a small increase in Free ATP is also evident along with a reduction in viable counts. With time there is a reduction in Total and Free ATP along with a further reduction in the plate count results. 

Cytochrome dehydrogenase, or indophenol oxidase, accompanies cytochromes in tissues (p. 195). 

Cu-+ Peroxidase Cytochrome oxidase Nicotinamide adenine dinucleotide (NAD) Hydride ion (H ) Alcohol dehydrogenase... 

Another pathway is the L-glycerol 3-phosphate shuttle (Figure 11). Cytosolic dihydroxyacetone phosphate is reduced by NADFl to s.n-glycerol 3-phosphate, catalyzed by s,n-glycerol 3-phosphate dehydrogenase, and this is then oxidized by s,n-glycerol 3-phosphate ubiquinone oxidoreductase to dihydroxyacetone phosphate, which is a flavoprotein on the outer surface of the inner membrane. By this route electrons enter the respiratory chain.from cytosolic NADH at the level of complex III. Less well defined is the possibility that cytosolic NADH is oxidized by cytochrome bs reductase in the outer mitochondrial membrane and that electrons are transferred via cytochrome b5 in the endoplasmic reticulum to the respiratory chain at the level of cytochrome c (Fischer et al., 1985). 

The cytochromes are iron-containing hemoproteins in which the iron atom oscillates between Fe + and Fe + during oxidation and reduction. Except for cytochrome oxidase (previously described), they are classified as dehydrogenases. In the respiratory chain, they are involved as carriers of electrons from flavoproteins on the one hand to cytochrome oxidase on the other (Figure 12-4). Several identifiable cytochromes occur in the respiratory chain, ie, cytochromes b, Cp c, a, and (cytochrome oxidase). Cytochromes are also found in other locations, eg, the endoplasmic reticulum (cytochromes P450 and h, and in plant cells, bacteria, and yeasts. 

Barbiturates such as amobarbital inhibit NAD-hnked dehydrogenases by blocking the transfer from FeS to Q. At sufficient dosage, they are fatal in vivo. Antin cin A and dimercaprol inhibit the respiratory chain between cytochrome b and cytochrome c. The classic poisons H2S, carbon monoxide, and cyanide inhibit cytochrome oxidase and can therefore totally arrest respiration. Malonate is a competitive inhibitor of succinate dehydrogenase. 

Nagy 1, G Schools, F Compermolle, P Proost, J Vanderleyden, R De Mot (1995b) Degradation of the thiocar-bamate herbicide EPTC S-ethyl dipropylcarbamoylthioate and biosafening by Rhodococcus sp. strain N186/21 involve an inducible cytochrome P-450 system and aldehyde dehydrogenase. J Bacterial 177 676-687. 

Tokimatsu T, Y Nagai, T Hattori, M Shimada (1998) Purification and characteristics of a novel cytochrome c dependent glyoxylate dehydrogenase from a wood-rotting fungus Tyromyces palustris. EEBS Lett 437 117-121. 

Alcohol dehydrogenases found in certain microorganisms utilize a pyrroloquino-line quinone (PQQ) or flavin cofactor to pass electrons released upon oxidation of alcohols to the heme electron-acceptor protein, cytochrome c. These membrane-associated alcohol dehydrogenases form part of a respiratory chain, and the energy from fuel oxidation therefore contributes to generation of a proton gradient across... 

Materials. Microspherical PGG glucan (Adjuvax, Alpha-Beta Technology, Worcester, MA) was prepared from Saccharomyces cereviseae strain R4 cells (11). Zymosan, cytochrome c (cyt c), bovine serum albumin (BSA), yeast alcohol dehydrogenase (ADH), Complete Freunds Adjuvant (CFA) and Incomplete Freunds Adjuvant (IFA) were purchased from Sigma Chemical Co. (St. Louis, MO). 

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